1. Field of the Invention
This invention relates to an apparatus and method for creating information and, more particularly, is suitably applied to a case of creating identification information based on blood vessels of a body, for example.
2. Description of the Related Art
There has been proposed an identification apparatus which performs an identification process by using a formation pattern (hereinafter, referred to as blood vessel formation pattern) of blood vessels unique to a body.
Such the identification apparatus images unique components, or blood vessels of a registrant, extracts a blood vessel formation pattern from the resultant blood vessel image, and registers this pattern in a prescribed database. This imaging is performed by using such characteristics that light of a near-infrared light bandwidth is specifically absorbed in deoxygenization hemoglobin (venous blood) or oxygenation hemoglobin (arterial blood) existing in blood vessels.
Then, to identify the registrant, the identification apparatus extracts a blood vessel formation pattern of the same unique components in the same manner as the registration process, and compares the extracted blood vessel formation pattern to the blood vessel formation pattern being registered in the database (for example, refer to Japanese Patent Laid Open No. 2003-242492).
By the way, the identification apparatus extracts blood vessel formation patterns with different accuracy due to noises. The noises are generated due to different imaging conditions in an optical system, such as an irradiation amount and irradiation strength, and physiologic change of imaging target between the registration process and the identification process. As a result, a rightful user may not be identified as a registrant.
Further, if a user uses different imaging apparatuses for registration and identification, the imaging apparatuses extract blood vessel formation patterns with different accuracy due to noises which are unique to the solid imaging elements of the imaging apparatuses.
As described above, the conventional identification apparatuses have different accuracy in extracting a blood vessel formation pattern due to noises, resulting in an unreliable identification process.